Interesting......wouldn't minda new VCR myself
The Age (Melbourne Australia)

Search for rogue radio signal

By GARRY BARKER
TECHNOLOGY EDITOR
Thursday 7 June 2001

Mystery radio transmissions from somewhere in the Mount Dandenong area are interfering with aircraft communications systems on the approaches to Melbourne Airport.

They are radiating on one of the VHF frequencies used by pilots to talk to air traffic controllers but, oddly, the interference occurs inside the aircraft, between the pilots, not between the pilots and the ground. It appears as "white noise" in the pilots' headsets, making speech impossible to hear.

A faulty video recorder in a house in Essendon was recently tracked down as the source of rogue radio transmissions that shut down one of the VHF channels used between pilots and air-traffic controllers at the airport. Richard Dudley of Airservices Australia said: "The VCR was radiating on our frequency out through the TV antenna on the roof. Our technicians tracked it down to the street and then to the house. We gave the people in the house a new VCR and junked the faulty one."

Mr Dudley said the latest problem was not a safety issue. "The pilots simply switch to another channel. But they have enough workload on take-off or landing without having to bother about radio interference. So we need to trace the source (of the rogue transmissions) and stop them." Technicians from Airservices Australia and the Australian Communications Authority have been trying for more than a week to trace the source of the problem. They say it is unlikely to be a malicious attack but is probably coming from faulty electrical or electronic equipment on the ground.

Interference with VHF channels is a constant problem for aviation communications experts. Rarely is it deliberate, although malicious attacks have been known.

Mr Dudley said: "We get interference from many sources, refrigerator motors in the process of burning out, for example, though they don't last very long.

"Our problem is that interference is usually intermittent, which makes it difficult to trace. In this case the transmissions are lasting up to an hour at a time, and then they stop."

ACA regional manager Peter Young confirmed the difficulty of the hunt. "If we can hear it, we can find it," he said. The problem was hearing it long enough to track it down.

"It's a stable frequency when it occurs but the trouble is that as soon as we get down to that level of investigation it seems to disappear. It's a Sherlock Holmes-type investigation. We just have to keep on doing our measurements until we can hone it down to a street and then to an individual house or business and eliminate the problem," Mr Dudley said.